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| author | Nadav Amit <namit@cs.technion.ac.il> | 2014-10-13 12:04:13 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-10-24 13:30:36 +0200 |
| commit | 13e457e0eebf0a0c82c38ceb890d93eb826d62a6 (patch) | |
| tree | f0ab042f6b4b419ec6cda09f0f199764636fda25 /arch/x86/kvm/emulate.c | |
| parent | KVM: emulate: avoid accessing NULL ctxt->memopp (diff) | |
| download | linux-13e457e0eebf0a0c82c38ceb890d93eb826d62a6.tar.xz linux-13e457e0eebf0a0c82c38ceb890d93eb826d62a6.zip | |
KVM: x86: Emulator does not decode clflush well
Currently, all group15 instructions are decoded as clflush (e.g., mfence,
xsave). In addition, the clflush instruction requires no prefix (66/f2/f3)
would exist. If prefix exists it may encode a different instruction (e.g.,
clflushopt).
Creating a group for clflush, and different group for each prefix.
This has been the case forever, but the next patch needs the cflush group
in order to fix a bug introduced in 3.17.
Fixes: 41061cdb98a0bec464278b4db8e894a3121671f5
Cc: stable@vger.kernel.org
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index eb3b1c46f995..97da5034d812 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3462,6 +3462,12 @@ static int em_bswap(struct x86_emulate_ctxt *ctxt) return X86EMUL_CONTINUE; } +static int em_clflush(struct x86_emulate_ctxt *ctxt) +{ + /* emulating clflush regardless of cpuid */ + return X86EMUL_CONTINUE; +} + static bool valid_cr(int nr) { switch (nr) { @@ -3800,6 +3806,16 @@ static const struct opcode group11[] = { X7(D(Undefined)), }; +static const struct gprefix pfx_0f_ae_7 = { + I(0, em_clflush), N, N, N, +}; + +static const struct group_dual group15 = { { + N, N, N, N, N, N, N, GP(0, &pfx_0f_ae_7), +}, { + N, N, N, N, N, N, N, N, +} }; + static const struct gprefix pfx_0f_6f_0f_7f = { I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov), }; @@ -4063,7 +4079,7 @@ static const struct opcode twobyte_table[256] = { F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts), F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd), F(DstMem | SrcReg | Src2CL | ModRM, em_shrd), - D(ModRM), F(DstReg | SrcMem | ModRM, em_imul), + GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul), /* 0xB0 - 0xB7 */ I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg), I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg), @@ -4993,8 +5009,6 @@ twobyte_insn: case 0x90 ... 0x9f: /* setcc r/m8 */ ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags); break; - case 0xae: /* clflush */ - break; case 0xb6 ... 0xb7: /* movzx */ ctxt->dst.bytes = ctxt->op_bytes; ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val |